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Retrofit Floor Heating Staple up Applications

One of the most common questions I hear from homeowners is: “I wish I could’ve (would’ve or should’ve installed) radiant floor heating in my home. I refer to this as the coulda-woulda-shoulda syndrome.

Fret no more. If you have a finished floor in your kitchen, bathroom or four season porch and have an unfinished room below, there is a simple retrofit floor heating application you can use incorporate the comfort of radiant floor heating by installing the STEP Warmfloor product to the underside of the floor from below. This method is referred to as a “staple up” or “between the joist” application. Below is a picture to give you a better idea of how the layers may look.

A visual display showcasing how layers may look

The STEP Warmfloor heating element is the perfect product for many applications. The STEP Warmfloor heating element is made of a thin polymer that is comprised of plastic and carbon black. You can even nail directly through this unique low-voltage product without worrying about damaging the element. This is possible because the product does not use a filament to create the heat.

When planning this retrofit floor heating installation, you will need to take into account the width of the floor joist as well as the length of each joist bay. There will be no need to install the element under cabinets above, as that will just be a waste of time and money. The STEP Warmfloor heating element is available in 12” and 9” widths. The 12” elements are used in applications where the floor joists are spaced 16” apart whereas two 9” elements are installed when your floor joists are spaced 24” apart.

After figuring what size of the element you’ll need and how much of it you’ll need to properly heat the floor above, you can install the elements to the subfloor beneath the room you’d like to heat. The heating elements can be stapled and/or nailed to the subfloor from below. Once this is complete, you will need to wire the elements together and then install a low voltage transformer. For many applications, the transformer(s) can be located in the same room, making the installation simple and fast. The final wiring would be a thermostat in the room above, if you choose to install one. Optional you ask? Yes; the STEP Warmfloor heating element does not necessarily need a thermostat to regulate its temperature. Find out more about this on our website .

After the wiring is complete, you will need to install some form of insulation. The purpose of the insulation in this type of retrofit floor heating project is to drive the heat directly through the subfloor and through the finished floor above. Either rolled fiberglass or 1-2” extruded polystyrene sheets work well for insulation. Both are readily available at your local lumber yard or big box stores. I prefer the rolled insulation blankets as they are easier to manipulate around wiring and plumbing connections. For the best results and comfort, try to install an R-value of R-11 or higher.

The next step is to turn the system on. Within one hour, you will be enjoying the unsurpassed comfort of radiant floor heating, all without compromising the existing tile, carpet, wood or vinyl floors. It’s that easy!